Improvement in rock-drilling engines



2Sheets'-Sheet1. E. EDWARDS. Rock-Drilling Engines.

Patented Dec. 15,1874.

wrrN E15 5E5 an W i IN'VENTOR TNE GRAPNIC CO. FNOTO'LITPLSQJ- 4-K PARKPLACE. N.Y.

UNITED STATES PATENT Orrron.

EDMUND EDWARDS, OF LONDON, ENGLAND.

IMPROVEMENT IN ROCK-DRILLING ENGINES.

Specification forming part of Letters Patent No.157,805, dated December15, 1874 application filed December 5, 1873.

To all whom it may concern.-

Be it known that I, EDMUND EDWARDS, of 38 Southampton buildings, London,England, have invented Improvements in Rock-Drillin g Engines; and I dohereby declare that the following is a full, clear, and exactdescription thereof, reference being had to the accompanying drawingsmaking part of this specifica tion, in which- Figure 1, Sheet 1, is alongitudinal elevation, partly in section, of part of a rock-boringmachine. Fig. 2 is a sectional plan of the same, and Fig. 3 alongitudinal elevation of the same. Figs. 4, 5, and 6 arecross-sections, Fig. 7 a back-end View, and Fig. 8 a front-end view, ofthe same. Fig. 9 is an end view of the parts which cause the rotation ofthe drill, and Fig. 10 is a cross-section of the valve. Fig.1]. isalongitudinal section of the selfregulating part of the feed apparatus.Fig. 12 is a longitudinal section, and Fig. 13 is an end view, of theapparatus which prevents the drill from rotating while making itsstroke. Fig. 14 is a longitudinal section, and Fig. 15 a cross-section,of the attachment of the drill to the piston-rod. Fig. 16 shows thearrangement of the movable nut in which the feedscrew works.

Similar letters of reference indicate corresponding parts in the severalfigures.

This invention relates to novel improvements in apparatus used fordrilling holes in rocks or other hard substances, in which apparatuspistons carrying a drill are made to reciprocate in a cylinder by thepressure of steam, air, or other fluid.

My improvements consist in novel methods of causing the piston toreciprocate, guiding it steadily during its cutting-stroke, and causingit to rotate during its return stroke, and of causing the drill toadvance by novel selfacting mechanism, exactly in proportion as thedepth of the hole increases.

The following description of my invention will enable others skilled inthe art to understand it:

In the annexed drawings, a is a cylinder, in which two pistons, b and b,work, which are coupled together by inserting the rod 0 of the piston binto a projection, z, of the piston b, and fastening the parts by a key,0. There is a projection, 70, similar to the one i on the rod 0, asshown. An inlet-port, d, is provided in the cylinder a, for admittingsteam or other fluid directly into the space between the two pistons,and an outlet-port, e, is also provided in the cylinder for the escapeof the fluid after it has done its work. There is a passage, f,

in the cylinder, which forms a communication between the lower end ofthe cylinder and the space between the pistons, and also a passage, 9,which forms a communication between the upper end of the cylinder andthe steamspace. h is a cylindrical hollow valve for regulating theinduction and eduction of the fluid. This valve is fitted upon the rod 0in the cylinder, and between the pistons b b, and is of such length thatit opens and closes the ports at the proper times, being caused toperform its movements by the projection tor 7c striking its end at thecompletion of each stroke of the piston. The valve h is provided with anannular groove, If, at its circumference, which forms a chamber orcommunicatingpassage between the exhaust-opening e and the ports f and galternately, and its stroke is limited by a set-screw, 71 fixed on thecylinder a, which extends into the groove h and prevents the valve,through its bearing-rings h, from moving any farther than the properdistance, either backward or forward. The back or forward movement ofthe valve instantaneously reverses, the action of the engine after eachstroke without any other valve-gearing whatever.

'The valve h may be cut at one side, as shown in Fig. 10, so as to beexpanded by the pressure of the steam within, and maybe madesufficiently strong opposite the cut to prevent such expansion frombeing too great.

h are longitudinal passages outside the central bore of the valve forthe steam to pass through on both sides. The port 6 may be made theinlet-port and the port d the outletport, and the passages f and 9 neednot then pass one another longitudinally, as shown. On the lower end ofthe cylinder to is formed the tube 1, through which works the pistonrodm, to which the drill is attached. The

tube l is bored out, and the piston-rod m, or a part of it enlarged forthe purpose, is fitted with recesses, in which elastic rings a a may beplaced, and the escape of steam is thus prevented without the use of astuffing-box.

The rotation of the pistons during their upstroke is caused by thetwisted prismaticbar 0, which passes into an opening in the rod 0, andis fixed to the cylinder-cover p, and upon which works the nut r, fittedin the piston b, and held in its place by a cross-plate. The

nut 1' has ratchet-teeth formed upon it, as

shown in Fig. 9, into which a pawl, .9, works, and the pistons are thuscaused to rotate during their upstroke, but are free to descend withoutrotation in their downstroke. In order to prevent their rotation duringtheir downstroke I form a straight groove or slot, t, on the piston-rodbetween the lower piston and the recess, at n n, as shown in Figs. 12and 13, which works through the ring a, which is formed with a keyfitting the groove t. The ring a can turn around freely, but isprevented from moving endwise by an annular groove around itscircumference, into which the screw 11 enters loosely. 00 is a smallcylinder formed radially to the cylinder at, and containing a pie ton orplug, which, when pressed down upon the ring a, holds the latter firmlyin its place, and the outer side of the cylinder 00 communicates, by thepassage y, with the steam-passage g, through which steam is admitted tothe upper end'of the cylinder a. When the pistons are rising the ring arevolves with the piston-rod as it rotates; but, when they descend,steam from the other end of the cylinder to forces the small piston orplug against the ring a and holds it firmly, so that it is almostimpossible for the pistons to rotate. A tongue or key upon the plughelps to hold the ring it inits place.

In order to feed the cylinder and drill forward as the depth of the holeincreases, the screw A is attached to the cylinder a, and revolves inbearings 13 B. It works in a nut, E, Fig. 16, attached to the cradle O,in which the cylinder a is fitted so as to slide backward or forward inthe grooves or guides D D. The nut E can be withdrawn from the screwwhen desired, so that the cylinder can be readily removed from thecradle, or replaced.

A tangent wheel, the teeth of which fit the screw A, and which can befixed, when required, may be used instead of the nut E. The screw A isworked by the ratchet-wheel F, Figs. 1 and 7, which is driven by thetooth or pawl G. This pawl is carried by a piston, H, which works in thesmall cylinder I, attached to the cylinder-cover 19. One end of thecylinder I communicates with the upper end of cylinder a, and its otherend communicates with the lower end of the cylinder (1, and the piston His thus caused to reciprocate backward and forward simultaneously withthe piston Z) I). The pawl Gr fits into a recess in the piston H, and ispressed out, by means of a spring, through a slot in the cylinder I, sothat, on its back stroke, it passes over the teeth of the ratchetwheel Fwithout causing the latter to revolve.

' In order to prevent the piston H from being moved when the drill hasmade a out not sufficiently deep, the valve K, Fig. 11, is fitted at theinner end of the steam-passage L, and prevents the admission of steam tothe cylinder I, unless the piston b has traveled sufficiently to liftthe valve, the edge of which projects into the cylinder for the purpose.

The screw A may be worked by hand by means of a wheel or handle, insteadof by the 'self-actin g arrangement described, without departing fromthe main principle of my invention.

In order to fix the drill to the piston-rod I make the latter hollow,and I fit the ring M, Figs. 14 and 15, round the drill ina slot in thepiston-rod, and I tighten the ring M by means of the key N, which isdriven between the ring and the outside of the piston-rod.

The drill is shown of smaller diameter where the ring M embraces it, andwhere the depth of the hole requires it can be drawn out and refixed ina fresh position.

Thecradle carrying the cylinder a is attached to a tripod or otherstandard by means of a hollow spherical plate, 0, Figs. 3, 7, and 8,which may have three bearing-points or projections upon it, and is drawnagainst a corresponding convex spherical plate by means of a bolt andnut or key, so as to allow a certain amount of universal motion to thecradle and drill.

Where there is sufficient difference between the area of the piston-rodm and the piston b the steam may constantly be admitted to the lower endof the cylinder, and the motion of the pistons causedby alternatelyadmitting and discharging steam from above the pistons, of which onlyone need be used, the position of the valve and steam-passages beingmodified accordingly.

The valve h need not be cylindrical, but may he sometimes used occupyingpart only of the cylinder, in end view.

In order to more rapidly discharge the steam or compressed air fromabove the piston b, Fig. 1, at the end of its downward stroke, Isometimes make a port or series of holes (shown in dotted lines at B,Fig. 2) through the cylinder, directly above the piston I), when in itsposition described, and communicatin g directlywith the exhau st-pipe orthe open air.- The piston 1) opens these holes and immediately closesthem again upon commencing its return stroke. This arrangement isapplicable to all cases in which the space between the two pistons ofsuch engines communicate with the outlet or exhaust, and the annularspace round the valve communicates with the inlet-pipe. A similar portor series of holes may be made immediately below the lower piston at thetop of its stroke, as shown in dotted lines at S, Fig. 2.

The apparatus described may be used to drive the ram of a pump,connected to the piston-rod or other machinery, instead of a drill.

The operation of my invention begins with the admission of motive fluidthrough the opening dinto the space between the-pistons b and b. Thevalve h covering the port f, the fluid goes into the port g follows thepassage g, and, through the port 9 arrives in the cylinder a between thecover 19 and the piston b, which latter is thereby moved down. It entersat the same time, through the passage i, into the cylinder I, and, bypushing the piston H forward, gives the feed-screw A a turn forward. Atthe same time the motive fluid enters the passage y, and presses theplug or against the ring it, which is thereby made rigid, and guides thepiston-rod m, and prevents its turning during this stroke. Theprojection 76 on the piston 12 comes finally in contact with the hub ofthe valve h, and carries it along until the port opens into the annulargroove 71. on the valve h, and the port f exposed to the motive fluid inthe cylinder between the pistons 12 and b, which enters the 'same, andis conducted by the passage f into the lower part of the cylinder abelow the piston b. If the valve K has been opened by the said piston inits descent, the motive fluid enters the passage 2, and therefrom thecylinder I, and moves the piston H backward, while the motive fluid atthe other end is discharged into the cylinder to, and from thereexhausted through passage 9 and the annular space It on the valve h intothe exhaust-port e. The piston 72 is now driven up and turned by theagency of the twisted bar 0, the ratchetwheel P, and the pawl S, turningthe ring it also, which is released from the pressure of the plug 00 bythe exhaustion of the motive liquid from the passage y into the passage9. Near the end of the upstroke the projection i strikes the valve h,and pushes it over the port-hole f, exposing the port 9 to the motivefluid, and the port f to the annular exhaust-chaniber 70 The motivefluid in the passage 2 and the left port of the cylinder I opens thevalve K, which has very little elastic pressure, and empties into thecylinder, whence it is carried off by the passage f and theexhaust-chamber h What I claim as my invention, and desire to secure byLetters Patent, is-

l. In a steam boring-machine, the combination of the revolvingpiston-rod, carrying pistons, and valve-movers, a valve fitted looselyupon the rod between the valve-movers, and the twisted bar for turningthe piston-rod, substantially in the manner and for the purpose hereinset forth.

2. The feed-screw A, ratchet F, and pawl Gr, connected to the cylinderas set forth, in combination with the guide, having a movable nut, E,attached to it, substantially as described.

3. The combination of the cylinder at, piston-rod, pistons b b, passage3 plug 00, ring a, and slot t, substantially in the manner and for thepurpose described.

4. The combination, with the cylinder I, piston H, piston b, and pawl G,of the passage L and regulating-valve K, for the purpose of preventing atoo rapid feed forward of the cylinder and drill, substantially asdescribed.

In tcstimon y whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

EDMUND EDWARDS.

Witnesses CHARLES JAMES WINTERSGILL, SIDNEY EVELYN GUYER.

